Titanosauria is a
globally distributed clade of sometimes extremely large Mesozoic herbivoroussauropod dinosaurs. On the basis of current evidence these giant dinosaurs seem
to have reproduced in specific and localized nesting sites. However, no
investigations have been performed to understand the possible ecological and geological
biases that acted for the selection of these nesting sites worldwide. In this study,
observations were performed on the best-known Cretaceous nesting sites around
the world. Our observations strongly suggest their eggs were incubated with environmental
sources of heat, in burial conditions. Taking into account the clutch composition
and geometry, the nature and properties of the sediments, the eggshells’ structures
and conductance, it would appear that titanosaurs adopted nesting behaviors
comparable to the modern Australasian megapodes, using burrow-nesting in
diverse media and mound-building strategies.

The original material
assigned to Laplatasaurus araukanicusHuene come from five different localities
in northern Patagonia (Argentina) where the Upper Cretaceous (Campanian) lies
exposed. This material includes several postcranial bones from multiple
specimens and showing different conditions of preservation, often lacking
anatomical overlap. The taxonomic status of the taxon is further obscured by
the absence of quarry maps of the multiple localities (lacking the recognition
of associated materials), and a proper designation of type material in its
original description. After Huene, new material was assigned to this taxon,
although none of it resolved the existing taxonomic issues. In 1979, the
designation of a lectotype (one tibia and one fibula) was the first stage in
the nomenclatural stabilization of the species. However, the assignment of the
remaining material to L. araukanicus remained uncertain. Here we review all the
material hitherto assigned to this taxon in order to clarify its taxonomic
status. We also provide a re-description of the lectotype and discuss the taxonomic
identification of material previously referred to this taxon. Lastly we include
it for the first time in an updated phylogenetic data matrix. Laplatasaurus
araukanicus is retained only for the lectotype. The material from Rancho de
Ávila is referred to cf. Bonitasaura sp. because they share diagnostic features
and are stratigraphically congruent. The remaining material is referred as
Lithostrotia indet. A phylogenetic analysis nests Laplatasaurus within Titanosauria
in a clade formed by ((Laplatasaurus + Uberabatitan) + (Bonitasaura +
(Futalognkosaurus + Mendozasaurus))).

A new ornithopod
dinosaur from the Upper Cretaceous (Maastrichtian) Snow Hill Island Formation,at James Ross Island, Antarctica is here described. This new taxon, named as Morrosaurus antarcticus gen. et sp. nov.,
is represented by a fragmentary right hind limb belonging to a medium-sized
individual. Our phylogenetic analysis nests the new taxon in a monophyletic
clade of Southern Hemisphere ornithopods that includes most Patagonian and
Antarctic ornithopods. Several members of this group share a slender and
bunched foot with narrow metatarsal IV, expanded chevrons, and bowed humerus
without deltopectoral crest. Several features indicate that these ornithopods
exhibit adaptations for a specialized cursorial mode of life. The recognition
of Patagonian and Antarctic Ornithopoda belonging to a monophyletic clade
reinforces palaeobiogeographical signals indicating that Patagonia, Antarctica
and Australia shared a common Late Cretaceous terrestrial fauna.